In such a conventional back illuminated photodiode 100 as shown in FIG. 24, in the superficial surface layer of an N-type silicon substrate 101 are formed a P+-type highly-doped semiconductor region 102 and an N+-type highly-doped semiconductor region 103. The P+-type highly-doped semiconductor region 102 and the N+-type highly-doped semiconductor region 103 are connected, respectively, with an anode electrode 104 and a cathode electrode 105. On the electrodes 104 and 105 are formed bump electrodes 106 made from solder. Also, the N-type silicon substrate 101 is thinned in the portion corresponding to the P+-type highly-doped semiconductor region 102 from the rear surface side thereof. The thinned portion functions as an incident part for to-be-detected light.
As shown in FIG. 24, the back illuminated photodiode 100 is packed into a ceramic package 107 by flip-chip bonding. That is, the bump electrodes 106 of the back illuminated photodiode 100 are connected to solder pads 109 provided on a bottom wiring 108 of the ceramic package 107. The bottom wiring 108 is connected to output terminal pins 110 through wire bonding. Also, on the surface of the ceramic package 107 is seam-welded a window frame 111 using brazing material 112. In the window frame 111 is formed an opening at the position corresponding to the thinned portion of the back illuminated photodiode 100, and in the opening is provided a transmissive window member 113 such as kovar glass for transmitting to-be-detected light.
Patent Document 1: Japanese Published Unexamined Patent Application No. H09-219421